Sulvanite is a very rare copper vanadium sulfide which rarely forms nice large crystals. Here, we have sharp crystals to 6 mm on nicely contrasting matrix of quartz. I hav enever seen crystals so big, but more importantly I amtold by those who do study such minerals, that these are very large or the species, and unusually well-isolated for display. An important locality specimen but beyond that, a super sulvanite for any locale.